This invention generally relates to child-resistant safety closures having an improved type of removal drive. More particularly this invention relates to a child-resistant closure of the two piece type which may be readily converted to a non-child-resistant closure by the individual dispersing the container to the user. An additional safety feature of the present invention is an embodiment including an extension of the depending skirt portion of the outer or inner cap in the form of a tear strip which must be torn away before the closure can be removed, providing visual evidence of tampering or previous opening of the container.
The disclosure of the present invention is related in part to the disclosure of U.S. Pat. No. 3,857,505 and to other commercially available 2-piece child-resistant safety closures. However, the present closure is believed to provide a more positive removal mechanism and also to provide a feature useful in converting the child-resistant closure to a non-child-resistant closure as well as an additional feature of construction providing evidence of tampering or previous opening of the container after manufacturing and initial filling.
Child-resistant closures are generally somewhat difficult to remove and thus present a problem to a patient with limited finger mobility. Previous closures providing convertible closures retain their convertible feature throughout the life of the container, allowing the user the option of converting the closure each time the container is used. The present invention provides a convertible closure which can be permanently converted to a child-resistant or a non-child-resistant closure at the time of initial use. This prevents the potential danger of a user inadvertently misusing such a closure in an area where children may have potential access to the container.